Propeller



June 18, 1929. G. QCHECKLEY 1,717,663

PRO/PELLER Filed Dec. 7, 1927 via; 2 l: Z :2a 7

Z/ Z5 Z4 Z4 Z4 5 INVENTOR GEORGECHEC/rZf/f Patented June 18, 1929.

UNITED STATES GEORGE CHECKLEY, OF NEW YORK, N.'Y.

PROPELLER.

Application filed December 7, 1927. Serial No. 238,434.

This invention relates to propellers and in particular to a combinationof propellers so arranged that they will give the maximum etficieutoperation, the same being an improvement over my Patent No. 1,607,116,granted November 16, 1926. A particular object of the invention is toprovide a plurality of propellers which can be mounted upon a singleshaft adjacent to each other, separated by various distances dependingupon their pitch and the conditions under which they operate and thesize of the propellers being so arranged that they will overcome theconditions which have heretofore been objectionable in the use ofpropellers.

A still further particular object of the invention is to provide a mainpropeller having positioned at the opposite sides thereof, auxiliarypropellers which may be of various sizes and which may be preferablyprovided with various numbers of blades. For instance, in the presentillustration of my invention the front propeller may have two blades,the main propeller three blades and the rear propeller four blades,although any number of blades may be provided on any one of thepropellers to suit the conditions.

To enable others skilled in the art to fully comprehend the underlyingfeatures of my invention that they may embody the same' in the variousmodifications in structure and relation contemplated, a drawingdepicting a preferred form has been annexed as a part of this disclosureand in such drawing, similar reference characters denote correspondingparts throughout all the views, of which,

Figure l is a view in side elevation of the end of a. propeller shaft.

Figure 2 is a view looking toward the rear of the propeller shaftshowing the propellers mounted thereon and showing also how they make asolid wall whereby the water will be effectively discharged toward therear, and

Figure 3 is a collective view of a plurality of different shaped shaftswhich may be employed in the mounting of the propeller whereby no lossof motion will be present and where the maximum turning effort can beemployed.

Referring to the drawings in detail, 5 indicates a shaft, in thisinstance, of triangular formation as illustrated in Figure 2, and uponwhich are mounted, a plurality of propellers. These propellers aresuitably spaced on the shaft and by way of illustration, 6 indicates thefront propeller, 7 the main or middle propeller and 8 the rearpropellers which are cast in the usual way to provide the. propellersleeves 9 and 10 and 11 respectively. The forward propeller aslllustratedis provided with two blades 12 and 13, which are identical insize and are of greater width adjacent their outer extremities, theblades themselves being relatively smaller than the blades of the mainpropeller 7 whose blades 14 are likewise widened at their uppermostportions and are cast integral as before stated, with the sleeve 10. Inthis instance there is provided three blades 14 which are equally spacedabout the periphery of the sleeve 10 in spaced relation with the main orcenter propeller 7, the propeller 8, which consists of four blades 15,which are also widened at their outer ends to give the maximum drivingpower, are of a diameter not to exceed 45% of the main propeller blades.

In this connection, it is to be understood that either the front or therear propeller or bdth may be of like size or may be of varying sizesbut in no instance is either propeller to exceed 45% -of the diameter ofthe main propeller. This I have worked out as beingnearly the rightproportion to obtain the maximum driving power from all three of thepropellers when used in combination.

It is a well known fact that the operation of the shaft and theoperation of the main propellers set up a partial vacuum around theshaft adjacent the base of the propeller blade and consequently a lossof driving power is the result.

In order to overcome this objection, I have made use of a relativelysmall front propeller, as illustrated, which will break up the body ofthe water and which will direct it toward the center of the mainpropeller and the main propeller in turn will churn the water up anddrive it rearwardly at which point the rear propeller will act upon itwith all four blades to obtain from the water the maximum pushing power.

It will be quite evident that the blades may or may not be in alignment,in view of the fact that their relative diametric relation willeffectively perform the work in an etlicient manner.

In order to hold the propellers on the shaft 5, I have provided endcollars 16 and 17 which are secured in position through the medium ofthe usual set screws 18. In order to separate the propellers any desireddistance, use is made of the spacing collars 19 and 20, the latter ofwhich, as illustrated, is longer than the collar 19 and thus thepropellers may be spaced any desired distance depending upon the resultsobtained as the result of experimentation.

In order that the maximum operation may be had, use may be made oftvarious shaped propeller bores and various shaped shafts upon which thesame may be mounted, and it will be noted in Figure 3, that a squareshaft 21 may be employed, a fluted shaft being illustrated at 22, whileat 23, there is shown a substantially diamond shaped shaft.

The other forms of the shaft indicated by the numeral 24 may be of anypolygonal shape and number 25 indicates a shaft, the sides of which havebeen flattened as at 27 to receive the collars and sleeves of thepropellers. Numeral 28 indicates a shaft, the diametrically oppositesides of which have been rooved as at 29 to provide a meansVll7l1efIt8T)y the propellers may be secured to the s 121 v It is to beunderstood that in all of the forms of the shaft shown in Figure 3, amatching bore will be provided in the propeller sleeve and in the collarseparating the .same in order that the maximum driving power may takeplace and slipping between the shaft and the propeller will thus beeliminated.

The propellers may be made of light construction and need not exceed theweight of the usual single propeller, because the great driving load isdistributed between the three propellers and consequently, they need notbe of as heavy construction.

It is evident, therefore, that in a propeller arrangement of this type,the greatest driving force will be obtainable and consequently thegreatest efiiciency arrived at due to the fact that suctions will not becreated at the base of the propeller blades and a greater drivingsurface will be provided.

It is evident also that variations in the sizes of the blades may bemade up to the limit noted and the blades may be spaced any particulardistance apart desired.

It is also evident that in conjunction with a main propeller, twoauxiliary propellers on the front and rear thereof may be provided forobtaining the maximum driving power.

While I have illustrated and described my invention with some degree ofparticularity,

a rear auxiliary propeller, the front propeller having a lesser numberof blades than said rear propeller and a main propeller disposed betweensaid auxiliary propellers.

2. The combination with a propeller shaft of a plurality of propellersmounted thereon and comprising a front auxiliary propeller, a rearauxiliary propeller, the front propeller having a lesser numbero-fblades and being of a lesser diameter than said rear propeller and amain propeller disposed between said auxiliary propellers.

3. The combination with a propeller shaft of a plurality of propellersmounted thereon and comprising a front auxiliary propeller, a rearauxiliary propeller, the front propeller having a lesser number ofblades than said rear propeller and one of said auxiliary propellersbeing of lesser diameter than the other and a main propeller disposedbetween said auxiliary propellers. 4. The combination with a propellershaft of a plurality of propellers mounted thereon and comprising afront auxiliary propeller, a rear auxiliary propeller, the frontropeller having a lesser number of blades t an said rear propeller andbeing of lesser diameter than said rear propeller, a main propeller.disposed between said auxiliary propellers and separating collars ofdifferent lengths between said propellers.

5. The combination with a propeller shaft of a plurality of propellersmounted thereon and comprising a front propeller having two blades, arear auxiliary propeller having four blades and a main propellerdisposed between said auxiliary propellers and being provided with threeblades.

In testimony whereof I affix my signature.

GEORGE CHECKLEY. 1. 3.

I therefore reserve

